1. Field of the Invention
The present invention relates generally to construction hand tools, and more particularly, a hand rasp with a groove blade for scoring surfaces, such as exterior insulation, so that functional and/or decorative grooves may be placed therein.
2. Description of the Related Art
A wide variety of hand tools have been developed and are currently available for scoring/etching grooves, and functional and/or decorative designs in construction material. Particularly, a variety of hand saws, rasps, utility knives and electrical hot knives are used to score, etch or groove exterior finish insulation systems (hereinafter “EFIS”) in preparation for subsequent coats of cement or mortar.
EFIS is an insulating material generally manufactured from polystyrene (or other similar material, such as available by the trade name STYROFOAM®) mounted to the skeletal frame of a building under construction. EFIS provides not only insulation to the building, but also a foundation for the exterior finish that will be prominently visible to patrons upon completion. After installation of EFIS, the insulation surface is smoothed by sanding. After sanding, the insulation must be scored, etched or grooved to accommodate functional and/or decorative markings required by building code or aesthetic design. For instance, if a large area of insulation has been applied to the building frame, it is often necessary to provide a starting/stopping point so that the application of subsequent coats of cement or mortar has a seamless visual appearance. Without starting/stopping points, the application of subsequent coats will appear messy and non-uniform, and may require complete re-work of the area. If functional grooves are required, such as a “drip-edge”, a precision score or etch must be applied to the insulation to prevent water from returning along a horizontal surface and then accumulating along a wall or the substructure, thereby damaging the wall or substructure. Decorative grooves, such as geometric designs or trade name indicia popular among commercial shops, are formed and defined by scoring/etching the insulation in the desired manner.
To install the aforementioned starting/stopping points (hereinafter “breaks”), or other functional and/or decorative grooves, many construction professionals employ hand saws, hand rasps or electrical hot knives to score, etch or groove the insulation. However, each of the aforementioned categories of hand tool suffers from certain deficiencies that render such use economically wasteful (in terms of time spent and impreciseness of tools leading to waste of construction materials) and/or unintentionally dangerous to use as required. These deficiencies are particularly acute and pronounced when construction proceeds at elevated heights, especially on scaffolding or extension ladders. The clumsiness of hand saws, with elongated and dangerously sharp blades, and hand rasps forces construction professionals to focus on several competing concepts at once, including safely using the tools, precisely scoring the insulation, and maintaining balance at the elevated height. To alleviate the concern for safety, time is spent harnessing the user into a safety apparatus so that loss of balance does not equal loss of life or severe bodily injury. However, the time spent harnessing the user, positioning the user, and then releasing the user from the harness is an inefficient and ineffective expenditure of valuable resources to the construction company, both in finances and time. Furthermore, to safely use these devices and precisely score the required grooves generally requires years of experience and expensive trial and error in coping with the conditions presented.
The electrical hot knife presents other additional problems as compared to manual hand tools. The electrical hot knife requires connection to an electrical source, generally accomplished by running a substantially long electrical cord from outlet to hot knife. At elevated working heights, the construction professional must negotiate the electrical cord, which often is approaching the professional from the feet and presents an increased likelihood of tripping or disconnecting the power from the hot knife. The precision of the blades in forming grooves is ultimately in the skilled hands of a user, but often minor misjudgments result in irreparable damage to the insulation. The imprecision of scoring insulation is further compounded if awkward angles of engagement are required, such as overhead use. Furthermore, the blades affixed to the hot knife for cutting varying configurations are manufactured from thin metal that is easily deformed and must be replaced often to ensure precise scoring. The necessity for repeated replacement of the blades creates additional expense, as each blade generally costs about twelve dollars ($12.00). The deformation of the blades causes imprecise scoring of the insulation, causing further delays and additional expenses. In addition, the blades are extremely hot and present potential burn injuries and/or damage to person or object during operation.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:                U.S. Pat. No. 4,669,970, issued in the name of Perry, discloses a hand tool for finishing corners with a cement material comprising an arcuately disposed plate for providing rounded corners;        U.S. Pat. No. 5,937,600, issued in the name of Larson, discloses a drip channel for use in the construction of exterior wall systems;        U.S. Pat. No. 5,979,058, issued in the name of Henke, discloses a multi-purpose contracting hand tool comprising a handle and a blade;        U.S. Pat. No. 6,032,320, issued in the name of McComber et al., discloses a trowel having imposed blade stresses imposed on the bottom and top working surfaces;        U.S. Pat. No. 6,095,435, issued in the name of Greer, Jr., et al., discloses an applicator system and method for stucco material comprising a dispensing assembly and a cartridge assembly;        U.S. Pat. No. 6,223,384, issued in the name of Kuhlen, discloses a trowel with a handle, wherein the handle does not possess a convention tang running in a longitudinal direction of the handle;        U.S. Pat. No. 6,415,472, issued in the name of Williams, discloses a circular edging tool for concrete, wherein the tool has a concave lip;        U.S. Patent No. Des. 333,600, issued in the name of Brandvold, discloses an ornamental design for a concrete groover having a V-shaped shaft; and        U.S. Patent No. Des. 453,672, issued in the name of McCoy, discloses an ornamental design for a sanding and cleaning device for drywall bullnose cornerbeads.        
Consequently, there exists a continuous need for new ideas and enhancements for existing products in the construction hand tool industry, especially the hand rasp disclosed herein that overcomes the deficiencies of presently available hand tools disclosed, thus providing an improved tool that is easy to use and maintain, cost effective for on-site use, and durable to withstand repeated usage in a variety of environments.